Zach,
I started off collecting (T206) HOFers and didn't get too far without getting a little bored. I don't have a big budget, so buying only HOFers restricted me to only buying one card here and there. So I decided to switch coarse. I started buying low grade commons instead of HOFers and have been much happier. I went from 15 cards to 70+ in no time. I'm not adding anything of significance at one time, but I really feel like I'm making much more progress than I was before.
As for your other question, I buy all of the commons raw. I've found that I can usually get a much better deal. Much of the hobby depends on TPG's for peace of mind. In my opinion this account for the higher prices on low grade cards, but it doesn't take long to develop an eye for reprints/alterations when you're looking at one set all the time. The HOFers I buy are graded (SGC for me)....just gives me peace of mind.